Influence of Surface Energy on Compressive Strength of Concrete under Static and Dynamic Loading

To clarify the compressive static and fatigue strength of concrete immersed in various liquids, experimental studies were conducted. The influence of the surface tension of immersion liquid on static and fatigue strength of concrete were examined based on the knowledge that (1) the fracture process of concrete at the macro scale is the result of generation and propagation of internal microcracks, (2) strain energy is partially released as surface energy when microcracks are formed, and (3) the magnitude of the surface energy between a solid and a liquid is affected by the surface tension of the liquid. The results indicate that the larger the surface tension of the immersion liquid, the smaller the static and fatigue strength of concrete, and that these are characterized by a linear relationship. It also became clear that the fatigue of concrete in air hardly matters whereas special attention should be given to the fatigue of concrete in the case of concrete structures that are frequently immersed in liquid with a larger surface tension than water, such as marine structures.